Junk mail filter

Question

Can anybody answer why the outlook junk mail filter is trash? I have an email that keeps going to junk even after I select that it’s not junk. It’s very frustrating that the filter can’t pick up that it’s emails that I do want

Answer 1

Dear Jason W,

Thank you for posting to Microsoft Q&A. I understand how challenging this situation can be, especially when important emails keep landing in your junk folder even after you've explicitly marked them as safe. 

While clicking "Not Junk" moves the selected email to your inbox, it does not permanently whitelist the sender. If Microsoft's security filters detect configuration issues with the sender's domain, future messages will continue to be routed to your Junk folder. 

To force Outlook to accept their emails, you will need to manually add them to your Safe Senders list. Please follow these steps: 

• Open Outlook, click the Home tab, and click the Junk dropdown button 
• Select Junk Email Options 
• Go to the Safe Senders tab 
• Click Add to manually type in the exact email address that keeps getting blocked 
• Click Apply and then OK 

I hope this helps you resolve the issue, and please let me know if you have any further questions! 

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Answer 2

Outlook’s junk filtering uses multiple signals (message content, sender reputation, past settings, and safe/blocked lists). Marking a message as “Not junk” moves that specific message back to Inbox, but it does not guarantee that all future messages from that sender will bypass junk filtering in every scenario.

To improve this behavior for the sender that keeps going to Junk in Outlook/Outlook.com, use these steps that are supported by the junk filter design:

1. Regularly review the Junk Email folder and mark messages as not junk:
   • Open the Junk Email folder.
   • Select the message.
   • Use Home > Report > Not Junk (classic Outlook) or the equivalent Not junk action in Outlook on the web.
   • This moves the message back to Inbox and helps correct misclassification.
2. Adjust junk protection level (classic Outlook for Windows):
   • Go to Home > Block > Junk E-mail Options.
   • On the Options tab, choose a less aggressive level such as Low or even No Automatic Filtering if junk is being over‑blocked.
   • Be aware that lowering protection can allow more spam into Inbox; review Junk Email regularly.
3. Use Safe Senders/Safe Recipients lists (classic Outlook):
   • In Junk E-mail Options, add the sender or their domain to the Safe Senders or Safe Recipients list so messages from them are treated as trusted.
4. If using Outlook 2016 for Mac:
   • From the Junk folder, select the message and choose Home > Junk > Not Junk or Mark as Not Junk to reclassify it.
   • For more reliability, add the sender to contacts or configure rules so messages from that sender are always delivered to Inbox.

Because junk filtering also happens on the service side, it can take some time and multiple corrections before behavior stabilizes. Continuing to mark the messages as Not junk and explicitly safelisting the sender/domain is the supported way to reduce these false positives.

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References:

• Overview of the Junk Email Filter in classic Outlook
• Change the level of protection in the Junk Email Filter in Outlook
• Label a message as "junk" or "not junk"